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Discussion Starter #1 (Edited)
I'm hopeing someone may be able to point me in the right direction with a rather annoying fault on my TS.

Fault:
I have an erratic idle basically

Symptoms:
You are driving along and the revs will 'blip' (a momentary loss of power, noticable). This doesn't happen very often though, but.....
You appraoch a red traffic light, put the clutch in and come to a stop, and take pot luck as to where the revs will be, 960, 1200, 1500, 2000. Then they'll fluctuate up and down. If you 'dab' the accelerator they normally drop back down to around 1000, but may only drop to around 1500, they then may drop again, or just carry on fluctuating.
Nothing is consistant, some days it'll idle reasonably well, some days it'll be a right git, and some it'll be somewhere in between.

What I've done:
Put it on FiatECUScan - Only fault codes have been that the fan sometimes doesn't come on (only spotted twice this year) And I've spotted that the Lambda sensor hasn't given a signal on two different occasions, but nothing consistant.
I went along the route that the MAF was faulty, so bought a new one and fitted it, no differance.
I've performed a ECU reset and cleaned the throttle body.
I've changed the spark plugs and air filter, and checked for leaks in the air pipe.

So what next:
I don't have a never ending supply of cash, so I'm trying to avoid just buying new parts 'willy-nilly' to see if it'll sort it.
I've done a lot of reading on here and seem to be leaning towards the Lamda sensor being faulty, maybe the heating ellement not working correctly. Would this caurse this sort of fault? Is it easy to replace, or a right pig to remove the old one (1999 2.0 TS), I assume it's only one sensor after the cat, is that right?
Or am I barking up the wrong tree altogether?

Any and all help is always appreciated, TIA
Dave
 

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Discussion Starter #2
Although either no-one has the knowledge of such faults on this site (which I doubt) or this site is full of members who simply cant be bothered to help out, I'll post what the end result was anyway, just in case someone is searching for help in the future!

I was directed to be looking in the area of the Idle Control Motor, either a simply re-sync or a replacement of the motor.
Position - This control motor bolts to the side of the throttle body and basically controls the butterfly during idle.
Now I'm told that it is possible to re-sync this unit using AlfaDiag (which I don't have) or FiatECUScan, which I do have but you have to pay for the registered version to be able to do this. Anyway I gave it a go and so far it is working perfectly and idling where it should.
But if it hadn't worked then I'd of needed to replace the motor, but then it would still of need the software to re-sync the replacement anyway.

Anyway, one re-sync later and I'm back to running properly again, which I'm happy with.
I hope this helps someone out in the future, I realise it's nothing special, but at least it's some help.
 

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Lambda sensors deteriorate with age and typically need replacing at around 60- to70,000 miles. If there's been a discontinuity in signal, I'd guess the sensor is on its way out and will need replacing sooner than later.

Whilst the cause of your idle issues was clearly the idle control unit in this case, a faulty lambda sensor will give very similar symptoms - idle speed jumping up and down randomly. They can also cause hesitation under acceleration and cause your fuel consumption to vary wildly.

Bear in mind the lambda sensor is the 'final arbiter' when it comes to the control of the fuel/air mixture your engine burns. The MAF measures the air on the way in, but the amount of fuel actually metered is corrected by the output from the lambda probe, so it's essential to have the lambda working properly.

Once you have a known-good lambda, it can give you very strong indicators about the health of the MAF sensor on the car. The output from the lambda is used to create both long-term and short-term fuel correction factors. The long-term is in effect the correction for any deviation from the curve exhibited by the MAF. It is normally a very small percentage. If it is large, it can be indicative of a faulty MAF (they usually fail lean) or possibly air leaks on the intake. Clever stuff!

Ian
 

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Although either no-one has the knowledge of such faults on this site (which I doubt) or this site is full of members who simply cant be bothered to help out, I'll post what the end result was anyway, just in case someone is searching for help in the future!
It's a common problem which you find a host of threads and posts if you try using Search, and as some of us are on BOTH sites, I didn't bother answering both ;)

But glad you got it sorted in the end.
 

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Discussion Starter #5
It's a common problem which you find a host of threads and posts if you try using Search, and as some of us are on BOTH sites, I didn't bother answering both ;)

But glad you got it sorted in the end.
And I do honstly appreciate all of your help bud :thumbs:
 

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Glad you sorted it :thumbs: but,

Although either no-one has the knowledge of such faults on this site (which I doubt) or this site is full of members who simply cant be bothered to help out...
That's hardly a fair statement...
 

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I do normally get involved in these as it's generally turns out to be the actuator, but must have missed this one. But having seen Dave's identical thread on the "other" forum, probably thought I'd responded!
 

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Discussion Starter #8
Glad you sorted it :thumbs: but,



That's hardly a fair statement...
Is it? My original request for help was posted on 25th October, and I got no replies on this forum! If I hadn't known of the other site I might of been struggling to sort this out (I may not, I appreciate that) This isn't my first post to be ignored, and I've noticed loads of others (I'm not all that knowledgable on the 156 enough to be able to help much, but I will if I can and someone else hasn't already given the correct answer!)
Don't get me wrong, I'm not new to this sort of thing, I'm a modorator over on 300ZX.CO.UK and have been a member there for over 8 years amongst various other car forums, so I know how it works.
Well anyway I'll keep helping where I can, as I've always given back no matter what.
 

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I think you'll find that this site is pretty well served and the help and suggestions are usually helpful.

Some recent posts on the other site have started to make me think why I bother with both. Any of you who subscribe to both will probably know it's where all our "banned" members end up, and they're not quite as fussy by the looks of things! ;)
 

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Discussion Starter #10
Well I never meant to offend, I was a little dissapointed in the response on this site, that's all.
But the main thing is I got it sorted thanks to your help Gary :thumbs: and I'll carry on enjoying the site, and I do enjoy this site as it's very informative, all be it you do have to do a lot of searching.
 

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No harm in bumping a thread, they can quickly disappear on a site this big :thumbs:
 

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DaveZed

Hello. It might be worth trying a search or just googling your problem...

usually links back to this site... and usually many solutions for most problems. Cheers:)
 

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More 156 2.0 TS erratic (or no) idling

I replaced the crank angle sensor (Alfa SA supplied) on my 156, Model 2002, 250 000 km, to cure erratic idling. Didn't work for me (very rich, stumbles, even got into the habit of dying in traffic, which was where the tacky hit the road).

We tried the pipe from the manifold, but the valve did seem to work. Didn't apply voltage to it, though. Possibly the (still original) lambda sensor in my case? Thanks all, :thumbs:for considering. VAEC
 
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